John married Harriet Wakefield in 1856. Harriet was born on 04 May 1837 in St Clair, St Clair County, Illinois; died on 22 Dec 1863 in Mercer, Mercer County, Missouri. [Group Sheet] [Family Chart]

1. Mary Elizabeth Duncan was born on 02 Jan 1857 in Mercer, Mercer County, Missouri; died in 1935 in Stockton, San Joaquin County, California.
2. Alfred G Duncan was born on 25 Dec 1858 in Mercer, Mercer County, Missouri; died on 27 Aug 1860 in Mercer, Mercer County, Missouri.
3. Harriet E Duncan was born on 28 Oct 1863 in Mercer, Mercer County, Missouri; died on 25 Jan 1864 in Mercer, Mercer County, Missouri.
4. ? Duncan

John married Mary Diana Brown on 08 Feb 1866. [Group Sheet] [Family Chart]

1. James Harvey Duncan was born on 07 Dec 1866 in Mercer, Mercer County, Missouri; died on 21 Jun 1955 in Lineville, Mercer County, Missouri.
2. Eliza Augusta Duncan was born on 01 Aug 1868 in Mercer County, Missouri; died on 04 Mar 1924 in Mercer County, Missouri; was buried in South Lineville Cemetery.
3. Susan Electa Duncan was born on 10 May 1870 in Mercer, Mercer County, Missouri; died on 29 Oct 1951 in Mercer, Mercer County, Missouri.
4. Sarah Iona Duncan was born on 26 Jun 1872 in Mercer, Mercer County, Missouri; died on 12 Mar 1915.
5. William M Duncan was born on 26 Aug 1875 in Mercer, Mercer County, Missouri; died on 18 Oct 1876 in Mercer, Mercer County, Missouri.
6. Vina Edith Duncan was born on 23 Aug 1877 in Lineville, Wayne County, Iowa; died on 27 Sep 1903 in Mercer, Mercer County, Missouri.
7. Arthur Carlisle Duncan was born on 18 Jul 1880 in Mercer, Mercer County, Missouri; died on 17 Aug 1884 in Mercer, Mercer County, Missouri.
8. Theodosia Eleanor Duncan was born on 08 Sep 1887 in Lineville, Wayne County, Iowa; died on 15 Mar 1966 in Berkeley, Alameda County, California.

Alfred married Eleanor C ?. [Group Sheet] [Family Chart]